Unity iPhone Quickstart: Button Tap Sledgenet.co.uk
http://www.into-games.com/sledgenet/unity-iphone-quickstart-b.
Sledgenet.co.uk Sledge's lil' corner of that World Wide Web thingy Skip to Content Home About Sledge The ComPile Ancient Texts Link-You-Do
Unity iPhone Quickstart: Button Tap
Mar 6th, 2010 by Sledge. There are a wealth of resources for Unity iPhone but, when starting out, I would really have appreciated a bunch of step-by-step tutorials showing how to achieve some of the fundamental things that games developers typically need to do. Being able set up an FPS controller in a couple of mouse-clicks is all well and good (in fact its awesome) but not much use if you dont actually want to make an FPS, hence this set of several short tutorials showing how to do some very specic, simple things with Unity iPhone. For anyone approaching Unity from a similar perspective to myself (ie being familiar with the iPhone and other development solutions but only casually acquainted with the engine) this stuff should hopefully help you to hit the ground running. So, with regards to the iPhone the three questions I wanted immediate answers to were How do I make a button that will respond to being tapped?, How do I pick meshes? and Whats the deal with serialisation? In this tutorial well deal with the rst of those: 1: Getting Started The rst thing to do is create a new project. There is no need to import the standard assets for the purposes of this tutorial.

1 of 8

4/27/10 5:27 PM
2: Class Acts We need something to happen when we tap our button so lets begin by creating a projectile prefab that we can re. A Unity prefab is akin to a custom type or class in an OOP language. From the main menu: GameObject>Create Other>Sphere In the Project View: Create>Prefab In the Project View:Create>JavaScript Rename the prefab to Projectile and the script to Projectile_AI. Drag the sphere from the Hierarchy View and drop it on the Projectile prefab in the Project View (the prefabs icon will turn solid blue). What we have done here is turn the sphere into a prefab, hence we no longer need the original ensure only the sphere is selected then press Apple+Backspace to delete it. 3: Oooh Behave! Now lets dene some behaviours for the Projectile class. Double-click the Projectile_AI script in order to bring up the Unitron editor. Edit the script thus:
var life = 100; function Update () { transform.position += Vector3.forward * 1.0; life -=1; if (life<1){ Destroy(gameObject); } }
Save the script. Pop back to Unity. Select the Projectile prefab so that you can see its components in the Inspector View, now drag n drop Projectile_AI on to the list of components, attaching the script to the prefab. This is a good time to wave your hands

2 of 8

majestically and pronounce Object, I grant thee BRAINZ!
Youll notice that the Life variable is exposed to the Inspector View and you can edit it to taste from here. 4: I Got Them Tappy Feet Fingers Finally, lets make a button to tap! From the menu: GameObject>Create Other>GUI Texture The default image for GUI Textures is the Unity watermark and, hell, itll do for now rename it Button and alter its x and y position to 1.5 in the Inspector View, placing it at the bottom-left of the screen.

Next we make a script to govern the GUI Textures behaviour. Create a new JavaScript in the Project View, rename it CheckButton then double-click it to bring up Unitron. Edit the script thus:

3 of 8

var shot:Transform; var recoveryTime = 10; private var delay = 0; function Update () { if (delay>0){delay -=1;} if (delay==0){ if(iPhoneInput.touchCount == 1){ var currentTouch:iPhoneTouch = iPhoneInput.touches[0];
if(currentTouch.phase == iPhoneTouchPhase.Began && guiTexture.HitTest(currentTouch.posit var shot = Instantiate(shot, Vector3 (0, 0, 0), Quaternion.identity); delay = recoveryTime; } } } }
The above, you will notice, is geared towards single touch input. For multi-touch input we can cycle through any existing touches in a loop, in which case the entire script would look like this:
var shot:Transform; var recoveryTime = 10; private var delay = 0; function Update () { if (delay>0){delay -=1;} if (delay==0){ for (var touchIndex = 0; touchIndex<iPhoneInput.touchCount; touchIndex++){ var currentTouch:iPhoneTouch = iPhoneInput.touches[touchIndex]; if(currentTouch.phase == iPhoneTouchPhase.Began && guiTexture.HitTest(currentTouch.position)){ var shot = Instantiate(shot, Vector3 (0, 0, 0), Quaternion.identity); delay = recoveryTime; } } } }
Back in Unity, select our Button from the Hierarchy View and drag the CheckButton script onto its list of components (in the Inspector View). You will see that the recoveryTime variable is exposed and can be edited whereas the delay variable, being private, is not. The other exposed variable is Shot, which is of the Transform type click on it to get a drop-down list and select Projectile. This lets the script know what kind of object Shot is meant to be when it is instantiated.

4 of 8

Click Play in the Game View if you are using Unity Remote, or Build & Run if you are opting to deploy straight to your iPod/iPhone (in which case remember to set an appropriate bundle name and nominate landscape mode From the menu: Edit>Project Settings>Player). Tap on the button and voila!

5 of 8

Cheers to: arzi and Sergey Fly from the Unity forums. Posted in: Unity. DeleD to Unity via Cheetah3D (phew!) Unity iPhone Quickstart: Mesh Pick Comments are closed.

Search

Type in and hit enter to search

Recent Blog Entries

The King Is Dead! Unity iPhone Quickstart: Mesh Pick

6 of 8

Blog Categories
Cheetah3D (1) DeleD (1) Game Review (PS2) (1) Scene (1) Site Admin (1) Unity (3)

Currently Playing

Wanted (Timur Bekmambetov)
Theres a spot in Wanteds convenience store scene where, for one glorious moment, it looks like Angelina Jolie might have a gun that res guns. She doesnt, but dont go thinking that the actual plot is any less ludicrous, the level of sanity on show exhibiting an inverse correlation to Bekmambetovs directorial vim. Lovingly realised cobblers. 04/14/10
Vantage Point (Pete Travis)
Apparently this has been criticised for over-egging the alternate perspective approach to storytelling but I thought it dumped the technique, sagely, just as it started to wear out its welcome. Neat idea, intriguingly laid out (oh and on the evidence presented here, Dennis Quaid shoulda replaced Harrison Ford for Indy IV). 03/14/10
Batman: Arkham Asylum (360)
My rst impressions will have to stand as my parting comments as it only took 3 evenings to dust off. Greater than the sum of its parts, innit. 03/13/10

Persona 3 FES (PS2)

It remains to be seen whether the slow narrative pace and impetus to nurture social links will grate on my nerves in the long term but, an hour or two in, the battle system seems full of promise. And the way Personas are summoned just, wow. 03/12/10

Plants vs Zombies (iPod)

7 of 8 4/27/10 5:27 PM
I wish Id thought of this! 03/12/10

Soul Calibur III (PS2)

Namcos continuing struggle to match the uidity of Soul Calibur (Dreamcast/XBL) is hella pretty just check out that rolling sea on the Pirate Raid stage but the balance is undeniably off. Mistakes so often lead to being mercilessly hammered that matches can feel all too random and some opponents seem to almost necessitate button-mashing. Its better than 90% of the genre all the same, but its no Soul Calibur. 03/12/10
2010 Sledgenet.co.uk | Powered by WordPress A WordPress theme by Ravi Varma

8 of 8